I was perusing the visual records page and stumbled across this gem. The basic concept is that, when you hold it, for every second the clock ticks, it'll add an hour to your life, but as soon as you let go of it, you have that number of hours left to live.

It's an interesting thing, really. The Foundation only really cares about containing these objects, but the reader wants something that'll make them feel - like fear, for example. SCPs are kinda like writing challenges: make a good story that fits a clinical tone.